Income Taxes - Schedule of Deferred Income Taxes (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Assets
Net operating loss carryforwards	$ 96.5	$ 71.6
Capital loss carryforward	1.6	1.7
ASC 606 - revenue from contracts with customers	8.4	9.9
Tax credit carryforwards	9.9	8.6
Stock-based compensation	7.6	7.7
Other comprehensive income	6.1	6.3
Inventory reserves	9.6	11.8
Reserves and other	5.2	1.5
Subtotal	144.9	119.1
Valuation allowance	(6.9)	(44.7)
Total assets	138.0	74.4
Liabilities
Accelerated depreciation	(194.5)	(189.1)
Accelerated amortization	(14.8)	(13.2)
Other	(8.8)	(6.0)
Total liabilities	(218.1)	(208.3)
Net deferred tax liabilities	$ (80.1)	$ (133.9)